Decorative laminated panels have many structural applications including walls and tops for furniture such as desks, tables and counters. Typically the decorative laminated panel includes a substrate or base formed from wood or wood by-products. A sheet of decorative material is adhered to the substrate and one or more top coats then are applied over the decorative layer to provide an attractive and protective finish.
The decorative layer of the panel usually is either a decorative vinyl between two and six mils thick or a paper imprinted with decorative inks to yield a desired color and/or pattern. In recent years the cost of vinyl has increased substantially, thereby making the vinyl coated decorative panels commercially less attractive. Panels produced with decorative papers generally can be manufactured at a lower cost than the corresponding vinyl clad panels and in many instances are considered to provide superior aesthetics.
Despite their lower cost and their desireable aesthetic properties, decorative papers have been too fragile for many types of panels. More particularly, the decorative layer of the panel easily could be damaged during normal use thus offsetting any initial aesthetic advantages of the decorative paper. The deficiencies of panels with layers of decorative paper are caused in part by both the fragile nature of paper and a poor bond of the ink to the paper. Furthermore many previously used top coats did not adequately penetrate the paper and ink, and thus the top coats were poorly bonded to the paper and ink. This drawback of top coats used with decorative panels having decorative paper layers has been particularly evident with photo-curable top coats. Photo-curable coatings are desireable because they are aesthetically attractive, they have good protective qualities and they can be cured very quickly. However, photo-curable coatings are also very viscous (100 c.p.s. to 3,000 c.p.s.). Thus they do not penetrate the ink and paper to fortify the two and to ensure a strong bond of the cured coating to the paper.
Several attempts have been made to provide improved laminated articles. For example, U.S. Pat. No. 2,430,479 which issued to Pratt et al shows that the bond between polymeric materials in laminated structures can be improved by coating the surface of the first applied polymeric layer with an isocyanate solution, subsequently allowing the isocyanate solution to flash off and then applying the second layer of polymeric material and heating the various layers together under pressure. U.S. Pat. No. 2,430,479 indicates that the disclosed process provides an enhanced bond which is due apparently to the reaction of the isocyanate to the polymeric materials on either side of it. Certain of the examples provided in U.S. Pat. No. 2,430,479 show: the bonding of alkyd resin to regenerate cellulose by means of a diisocyanate; the bonding of nitrocellulose to regenerated cellulose by means of an alkyde resin and a diisocyanate; the bonding of cellulose nitrate to cellulose with a diisocyanate; and the bonding of nitrocellulose to regenerated cellulose employing polyvinyl butyral and a diisocyanate.
U.S. Pat. No. 2,804,400 which issued to Kelly et al is directed to a wood coating method to be used for baseball bats, bowling pins and the like. More particularly U.S. Pat. No. 2,804,400 shows first applying at least one polyisocyanate-containing ethyl cellulose layer to the bare surface of the wood and subsequently applying at least one layer of an ethyl cellulose coating composition. One embodiment of the method shown in U.S. Pat. No. 2,804,400 shows the application of a polyisocyanate compound to the bare surface of the wood as a primer before the application of the polyisocyanate containing ethyl cellulose layer. The disclosure of U.S. Pat. No. 2,804,400 indicates that the resulting laminated structure is protected well against damage from impact and deterioration.
Another laminated structure is shown in U.S. Pat. No. 3,687,801 which issued to Derby and is directed to a process wherein a cellulosic substrate such as hardboard, particle-board or plywood is first coated with an adhesive of acrylates and isocyanate in a toluene solution. The coated substrate of U.S. Pat. No. 3,687,801 then is convection dried by passing through an oven and then is coated with an acrylic film which is pressed on at about 250.degree. F. As stated in U.S. Pat. No. 3,687,801 the adhesive applied intermediate the acrylic film and the cellulosic substrate yields a laminated structure with substantial peel resistance.
Still another laminated structure is shown in U.S. Pat. No. 4,104,432 which issued to Manabe et al and shows molded plastic articles which are coated initially with a thin metal film and then with a paint having a polyisocyanate therein. As shown in U.S. Pat. No. 4,104,432, this initial paint layer is cured by heating and a second coat of paint then is applied and is cured by ultra-violet rays.
Other laminated articles are shown in U.S. Pat. No. 2,911,321 which issued to Herrmann et al, U.S. Pat. No. 3,117,019 which issued to Cohnen et al, and U.S. Pat. No. 3,198,692 which issued to Bridgeford.
Although certain of the above identified disclosures show various methods that purport to improve laminated structures, none of the disclosures are directed to laminated structures wherein one of the layers is a fragile decorative paper which has been imprinted with a decorative ink. More particularly, none of the above identified disclosures suggest improved decorative panels employing ink imprinted decorative papers. Furthermore none suggest the use of photo-curable coatings with decorative papers.
Accordingly, it is an object of the subject invention to provide an improved decorative panel.
It is another object of the subject invention to provide a decorative panel with a decorative paper layer.
It is a further object of the subject invention to provide a decorative panel which is aesthetically attractive and resistant to damage.
It is still another object of the subject invention to provide a decorative panel in which the decorative paper and the inks therein are fortified, protected and adequately adhered to adjacent layers.
It is yet another object of the subject invention to provide a decorative panel with decorative paper layer and a photo-curable top coat.